Waterproof coating.



UNITED STATES PATENT OFFIGE.

WILLIAMA. HALL, OF BELLOWS FALLS, VERMONT, ASSIGNOR TO THE OASEIN COMPANY OF AMERICA, A CORPORATION OF NEW JERSEY.

WATERPROOF COATING.

SPECIFICATION forming part of Letters Patent No. 684,509, dated October 15, 1901.

1 Application filed eptember 12,1899. Serial No. 730,242. (No specimens.)

lows Falls, in the county of \Viudham and State of Vermont, have invented certain new and useful Improvements in \Vaterproof Coatings, of which the following is a specifi cation. U

This invention or discovery has for its object to produce a waterproof porous coating especially adapted for use in enameling playing'cards and other similar paper articles to which it is desired to impart glossy Water-repellent surfaces which are still sufficiently porous to take printing-ink.

This improved sizing or waterproofing composition consists of a base preferably of satin- White (precipitated sulfate of calcium) and casein dissolved in a suitable alkali (preferably carbonate of soda or ammonia) and Water. Instead of using satin-White alone as a base a mixture of satin-white and clay or blanc fiXe maybe employed. The preferable proportions of these ingredients, by weight, in a dry state are about eighty parts of the base, twelve to sixteen parts casein, and two to four parts alkali, although these proportions are capable of some slight variations. Some twenty-five parts or rather more of Water will be added in mixing the ingredients for use.

The action of satin-white upon an alkaline solution of casein is peculiar in that it causes such solution to become insoluble as soon as dry and seasoned, While a coating consisting of satin-White and an alkaline solution of casein, although insoluble after it hasbeeu dried, is still sufficieutly porous to readily take printingink. In other words, there is a chemical combination between satin-white and casein which has been dissolved in an alkali, the satin-White rendering the alkaline solution of casein insoluble as soon as the coating is dry and seasoned.

The mineral coating produced according to the present invention or discovery has been found especially valuable in giving an enameled surface to playing cards and similar printed paper or cardboard articles, for the reason that the porous glossy surface which it produces is Well adapted to receive colored printing-inks, Which are readily taken up by this porous coating, so that the lines of the printing come out fine and clear. In the use of this porous glossy coating the fibers of the paper are Well covered, so that the printingink will come upon the coating and not on the vegetable fiber of the paper.

Having thus described my invention or discovery, I claim and desire to secure by Letters Patent A Waterproof porous composition for coating paper and the like, consisting of a base comprising satin-white, and casein which has been dissolved in an alkali, substantially as hereiubefore set forth.

In testimony whereof I affix my signature in the presence of two Witnesses.

IVILLIAM A. HALL.

Witnesses:

P. H. HADLEY, A. H. CHANDLER. 

